Simon, not only do you totally get the inherent advantages and joys of pie menus, and have the skills and persistence to implement them well and iterate on the design by continuously using and refining them over many years (at least a dozen years since you made trace and coral menus, right?), but you also have an impeccable sense of design and creativity, and they look really great!

And the best part is that you've implemented an easy-to-use elegant wyziwyg drag-and-drop editor so anybody can edit and design their own pie menus, without writing json, xml, or code. Which is extremely important because everyone has their own personal use cases and important commands they need to select quickly.

Thanks for all your work, and for making it open source, and going the extra mile to make it cross platform (which is extremely difficult)!

I've written about how much I like your previous work before:

https://news.ycombinator.com/item?id=17106453

DonHopkins on May 19, 2018 | parent | context | favorite | on: Pie Menus: A 30-Year Retrospective: Take a Look an...

I'm very impressed by Simon Schneegans' work on Gnome-Pie:
http://simmesimme.github.io/gnome-pie.html

And especially his delightful thesis work:

Trace-Menu:

https://vimeo.com/51073078

I really love how the little nubs preview the structure of the sub-menus, and how you can roll back to the parent menu because it reserves a slice in the sub-menu to go back, so you don't need to use another mouse button or shift key to browse the menus.

Coral-Menu:

https://vimeo.com/51072812

That looks like a nice visual representation with a way to easily browse all around the tree, into and out of the submenus without clicking! I can't tell from the video if it's based on a click or a timeout. But it looks like it supports browsing and reselection and correcting errors pretty well! (That would be something interesting to measure!)

There's another useful law related to Fitts's law that applies to situations like this, called Steering Law:

https://en.wikipedia.org/wiki/Steering_law

The steering law in human–computer interaction and ergonomics is a predictive model of human movement that describes the time required to navigate, or steer, through a 2-dimensional tunnel. The tunnel can be thought of as a path or trajectory on a plane that has an associated thickness or width, where the width can vary along the tunnel. The goal of a steering task is to navigate from one end of the tunnel to the other as quickly as possible, without touching the boundaries of the tunnel. A real-world example that approximates this task is driving a car down a road that may have twists and turns, where the car must navigate the road as quickly as possible without touching the sides of the road. The steering law predicts both the instantaneous speed at which we may navigate the tunnel, and the total time required to navigate the entire tunnel.

The steering law has been independently discovered and studied three times (Rashevsky, 1959; Drury, 1971; Accot and Zhai, 1997). Its most recent discovery has been within the human–computer interaction community, which has resulted in the most general mathematical formulation of the law.

Also here's some interesting stuff about incompatibility with Wayland, and rewriting Gnome-Pie as an extension to the Gnome shell:

http://simmesimme.github.io/news/2017/07/09/gnome-pie-071